QuestionI have a large garden that I wanted to reduce the size for vegetables. I double rototilled the extra area, raked it flat and planted 2 large containers of wildflower mix for my area. Zone 5 in Ohio I watered faithfully as directed and got the best crop of weeds ever. I weed-whipped them down when they reached my waist and before they seeded. They came back and I beat them down again. I got only 2 flowers. How can I kill the weeds so I can grow the wildflowers? Thank you.
AnswerThey sure make it sound easy to have a field of wildflowers instead of grass and weeds, don't they?
You have found out that there were a lot of weed seeds in the area. Some remain viable for as long as twenty years if not longer. Although you cut the first crop of weeds before they made seed, there were plenty of seeds still left in the soil.
You can drastically reduce the number of weeds by retilling the area as soon as the first spring crop of weeds is a couple of inches high and repeating this through an entire season. Then sow the wildflower mix in September unless the package gives you a different recommendation. If they say to sow in the spring, keep tilling at intervals (the previous year) until it is so cold that no more seeds germinate.
In my wildflower propagation class in college we lined seed tray flats (11x22 or so) with thick layers of newspaper, filled them with seed starting mix and sowed the wildflower seed mix in March. In May we separated the seedlings into small bunches and planted the plugs a foot or two apart in a field that was tilled the previous season. This, of course, is not something you want to do in large areas. You can apply a pre-emergent weed killer to the area before planting the plugs and it will suppress most of the weed seeds. Nothing works a hundred percent. When weeds appear, you can do a bit of hoeing or hand-pulling the largest ones.
You will find that the wildflowers will gradually diminish in number and variety over a few years until you are back to just weeds and grasses.
